Reply, ReplyAll and Forward buttons are not appearing on EmailMessage layout of claim related record

Question

EmailMessage record is created/inserted from apexclass implements Messaging.InboundEmailHandler

          fromAddress is from external mail - @gmail
          Snippet here :- Related to is claim id

        EmailMessage emailMsg = new EmailMessage();
        emailMsg.ToAddress=(toAddress);
        emailMsg.FromAddress=inboundEmail.fromAddress;
        emailMsg.Subject=inboundEmail.subject;
        emailMsg.HtmlBody=inboundEmail.htmlBody; 
        emailMsg.TextBody=inboundEmail.plainTextBody;
        emailMsg.Status = '0';
        emailMsg.RelatedToId = claim_temp.Id;

without the buttons, if relatedto is case id then i can see with the buttons

Answer 1

Do you have "Allow Activities" ticked on that Claim object? Will be in object's "header" config, next to "Allow Reports". Sending emails out is part of the Task/Event functionality.

Is that in same sandbox? If it's different environments - you might have Setup -> Deliverability turned off.